Joining system for triangulated structures

ABSTRACT

The invention is directed to structural elements for use in triangulated structures, and structures assembled from such elements. In particular the invention provides an elongated structural element for use in a triangulated structural assembly, provided at at least one end thereof with connector means adapted for pivotal connection directly to at least one further structural element about a pivot axis which is transverse to the longitudinal axis of the structural element and which is disposed outside the general envelope of the structural element itself. The arrangement is such that from two to as many as one hundred such structural elements may be interconnected at a structural node without the use of an intermediate nodal member.

This application corresponds to and claims the priority of BritishApplication Ser. No. 41000/77, filed Oct. 3, 1977 and PCT/US78/00100,filed Oct. 3, 1978, which claimed priority therefrom, but which wasabandoned in favor of the present application.

FIELD OF THE INVENTION

The present invention relates to building structures havingprefabricated components whose struts must be joined, and in particular,to a hinge joining arrangement for interconnecting the struts oftriangulated space frame type structures.

DESCRIPTION OF THE PRIOR ART

Triangulated framework space structures include planar space frames forbuilding roofs and walls, domes, such as geodesic domes and the like,and complex convexoconcave structures. Such structures possess a certainsymmetry and direction characteristic such as is explained and describedin my earlier issued U.S. Pat. No. 3,600,825, and Great Britain Pat. No.1,354,965. Such building structures frequently comprise planar memberswhose planes are defined by peripheral struts joined to adjacentstructural plane members at the strut ends. An improved strut systemwhich utilized a novel gusset clamp which interconnected strut membersat preselected angles is disclosed in my copending application Ser. No.817,512, filed July 21, 1977 and now abandoned for GUSSET CLAMP JOININGSYSTEM FOR TRIANGULATED SPACE STRUCTURES.

Except these approaches, the classic and pervasive solution to theproblem of joining a plurality of struts at a single point is to jointhe struts to an additional nodal element or component. Such an approachis exemplified by the so-called German "Mero" system described byBorrego, Space Grid Structures, (the MIT Press, 1968) at pages 18-21,and by the so-called U.S. "Unistrut" system, at pages 30-33 of theBorrego, and the "Triodetic" system from Canada.

It has long been thought to continue improvements in such prefabricatedlinear strut members so that they may be joined at their ends simply,and with fewer parts so to facilitate their assembly into a fullytriangulated framework space structure where a plurality of strutmembers meet at a typical, nodal domain.

One such approach was described in the patent to R. B. Fuller, No.2,986,241, issued May 30, 1961, for "SYNERGETIC BUILDING CONSTRUCTION".In FIGS. 7-13 inclusive, strut members were shown which terminated ingenerally "X" shaped ends that were drilled to receive fasteners. Thedrilled ends or flanges were arranged in what Fuller termed"overlapping" or "plus or minus turbining" and appear to be joined in anode including six axii or struts radiating outwardly from the centre ofa hexagon with three struts as the apex of a tetrahedron below and/orabove the node. All struts were of the same length and all structureswere based on a common octahedron-tetrahedron system.

SUMMARY OF THE INVENTION

According to the present invention a system is disclosed which providesmuch greater versatility at lower cost than other systems including thatof Fuller (supra). The system is predicated on the principle that nocentral nodal component is required (whether said nodal component ishomogeneous or segmented), but that the ends of the struts themselvesmay be attached one to another directly, thereby eliminating the need(and therefore the manufacturing complexities, cost and weight) of anodal component. Fuller, while avoiding the nodal component, teaches astructure that generally requires the interconnection of at least threebut generally more struts at each "node".

The means by which such joining of struts together without use of nodalcomponents may be called the "polyhinge" or "multi-hinge" joiningsystem. Such multi-hinge joints enable as few as two strut ends to bejoined at a single "nodal domain", or as many as 100 or more to bejoined at a single nodal domain. This versatility is not matched by anyother joining system, except the earlier gusset clamp joining system ofthe copending application.

The multi-hinge joint system consists generally of paired, hinge-likeelements. Such hinge-like elements can take many forms. In general, eachhinge half is attached to a strut end such that two strut ends may bejoined by means of a nut and bolt or other hinge pin equivalent.

In order to join a plurality of struts together at a single nodaldomain, each strut end is joined to its nearest neighbour (and in someinstances its next nearest neighbour as well). As a result, each strutend is usually connected, by means of the multi-hinge joint, to twoneighbouring strut ends, although in certain cases each strut end can beattached to three, four or six neighbours. Since the multi-hinge jointcan adjust to any required angle, the joint elements can bestandardized, while accommodating an extraordinary range ofconfiguration and degree of complexity.

Because triangulated structures have inherent geometric stability, rigidspace frames are produced in spite of the fact of a hingeableconnection. Also, because the struts are attached directly, one toanother, without the intermediary of a central nodal connection,multiple polyhinge joint stability is insured. This overall jointstability results directly from the angular stability about eachpolyhinge joint which is provided by the triangular frame to which itbelongs as one of its three apices.

Indeed, localized joint stability is so completely dependent upon theglobal geometric stability of a structural frame, that any combinationof struts meeting at a nodal domain, provided that the structure towhich they belong is stable, will form a stable joint. As few as threeand as many as 6, 8, 10, 14, 26 or ever 100 struts meeting at a nodaldomain will be stable.

In alternative embodiments, the hinge elements may be as simple as anapertured flange fastened to the exterior surface of a strut memberwhich functions as a single shear connector element. More complex hingescan include double and triple shear versions.

In a double shear hinge connector, the yoke or female hinge elementswould be placed on both ends of a strut. The complementary central, ormale hinge element would then be placed at both ends of a second strut.This embodiment requires a doubled inventory of "male" and "female"struts.

A triple shear embodiment is also possible. Here, however, only a singlehinge element is required since each is a yoke element, and two yokescan be easily connected together. The various embodiments can beconnected by bolts, threaded fasteners or pins. If pins are used, theycan be secured by split ring washers, sometimes known as circlips orwith cotter pins.

The novel features which are believed to be characteristic of theinvention, both as to organization and method or operation, togetherwith further objects and advantages thereof, will be better understoodfrom the following description considered in connection with theaccompanying drawings in which a preferred embodiment of the inventionis illustrated by way of example. It is to be expressly understood,however, that the drawings are for the purpose of illustration anddescription only and are not intended as a definition of the limits ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 including FIGS. 1a and 1b are end and side views, respectively,of a typical multi-hinge, single shear element;

FIG. 2 is comprised of FIGS. 2a-2d in which FIG. 2a is a side view oftwo multi-hinge elements of FIG. 1 fastened to a tubular strut member,FIG. 2b is a perspective view of the strut of FIG. 2a, and FIGS. 2c and2d are a side and perspective view, respectively, of two struts joinedtheir hinge elements;

FIG. 3 including FIGS. 3a-3e, are end views of struts with from two tosix multi-hinge elements attached at various orientations;

FIG. 4 including FIGS. 4a-4e, are end views of a plurality of strutswith multi-hinge elements attached in which the elements at therelatively remote end of the strut are shown as shaded so that therelationship between the radial orientation of the hinge elements at oneend and at the other end can be observed;

FIG. 5, including FIGS. 5a-5e are end views of square struts to whichmulti-hinge elements have been applied;

FIG. 6 including FIGS. 6a-6c, illustrates multi-hinge elements attachedto a triangular strut;

FIG. 7 including FIGS. 7a-7c, illustrate the application of multi-hingeelements to a hexagonal tube with shading utilized to differentiate themulti-hinge elements positioned at the near end of the strut from thoseat the far end of the strut;

FIG. 8 is a perspective view of a strut according to FIG. 6a beingjoined to a strut according to FIG. 5a;

FIG. 9 including FIGS. 9a-9c, are end views of various arrangements ofinterconnected struts;

FIG. 10 is a side, partially perspective view of eight struts beingjoined in a common vertex;

FIG. 11 is an end view of three struts being joined together with aconnector that is adapted to attach other structural elements;

FIG. 12 is a perspective view of a pair of struts with double shearhinge elements being connected;

FIG. 13 including FIGS. 13a, b and c are respectively a perspectiveexploded end and side views of a tubular strut member utilizing a plughaving double shear hinge elements;

FIG. 14 including FIGS. 14a and b are an end view and a side viewrespectively of the struts of FIGS. 13 joined together;

FIG. 15 is a perspective view of a pair of struts joined togetherutilizing a triple shear hinge element;

FIG. 16 including FIGS. 16a and b are an exploded and connectedperspective view respectively of a pair of single shear hinge elementsattached to tubular struts joined by a bolt member;

FIG. 17 including FIGS. 7a, b, c and d are end and side viewsrespectively of a tubular member including four multi-hinge elements andthree multi-hinge elements;

FIG. 18 is a perspective view of three strut elements of FIG. 17 joinedtogether;

FIG. 19 is an end view of five strut elements joined together with theirrespective hinges;

FIG. 20 including FIGS. 20a and b are end views of tubular struts inwhich panel members are joined to a strut member using the multi-hingeelement and showing the connections of a multi-hinge element; and

FIG. 21 including FIGS. 21a and 21b are end views of still anotherembodiment of a multi-hinge strut element with attachments to the hingeelements.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Turning first to FIG. 1, which includes FIGS. 1a and 1b, there is shownan end and side view, respectively, a preferred embodiment of a typicalmulti-hinge element 12. As shown, the element includes a hinging portion14 and an attaching portion 16. The hinging portion 14 includes anaperture 18 to which a fastening element may be used to connect twohinge elements together.

As best seen in FIG. 1a, the typical multi-hinge element 12 is designedfor attachment to a tubular strut member 20. The curvature of theattaching portion 16 is designed to conform to the radius of curvatureof the tube 20 and the hinging portion 14 is then angled so that theattaching surface is in a plane 22 that includes the central axis 24 ofthe strut 20. In the preferred embodiment, the pivotal or hinge axis 26of the multi-hinge element is then perpendicular to the plane 22.

The multi-hinge element 12 may be fastened to the tubular strut 20 bymany techniques, depending upon the materials employed. Preferably, ajoining technique is used which results in a strong bond between thestrut and hinge. Multi-hinge elements can easily be produced in avariety of shapes and styles and in many different materials and bymeans of varying techniques. Iron, steel, aluminium, and reinforcedplastics may be used.

In the case of metallic materials, the techniques suitable for massproduction of the hinge elements may include stamping, casting, forgingand sintering and joining techniques including welding and brazing. Ifplastics are to be used, injection and compression moulding may be usedin addition to stamping and forming and comparable joining techniquescan be used with the inclusion of adhesives, as well.

As seen in FIG. 1b, the hinge element 12 may be elongated in the axialdirection to provide a greater bonding area to the strut 20 and tosupply additional resistance to twisting.

Turning next to FIG. 2 which includes FIGS. 2a-2d, a typical tubularstrut element 30 is shown in side view in FIG. 2a and in perspective inFIG. 2b. As shown in FIG. 2a, the strut element 30 has welded to it twomulti-hinge elements 12 separated by 180°. As can be seen from theperspective view of FIG. 2b, a plane passing through the central axis ofthe strut 30 that is tangent to the hinging portion 14 of one of themulti-hinge elements 12 will also be tangent to the other multi-hingeelement hinging portion, but on opposite sides of the plane.

The interconnection of two similar struts 30 is illustrated in side viewand in perspective view in FIGS. 2c and 2d respectively. As shown, afastening element 32 serves as a hinge axis and aligns the two strutelements so that their central axes are coplanar. In FIGS. 2c and d, thefastening element 32 is a hinge pin nut and bolt.

In FIG. 3 which includes FIGS. 3a-3e, several alternative multi-hingeelement placements are shown for a strut member. As in the Fullerpatent, the attaching surface of each hinge element 12 is tangent to aplane through the centre of the strut and hinge elements which areradially positioned 180° apart are on opposite sides of a common plane.

In FIG. 3a, a strut member is illustrated with a pair of hinge elements12 separated by 180° while FIG. 3b illustrates a strut with twomulti-hinge elements separated by 90°. In FIG. 3c, there is shown anembodiment which in effect, combines the showing of FIGS. 3a and 3b toresult in a strut with three multi-hinge elements positioned, utilizinga "clock notation" at 12 o'clock, 6 o'clock and 9 o'clock. Equallyspaced multi-hinge elements are shown in FIGS. 3d and 3e wherein fourequally spaced elements are shown in FIG. 3d and six equally spacedelements are shown in FIG. 3e.

Turning next to FIG. 4, there is illustrated several possiblealternative combinations and angular positionings in the attachment ofthe multi-hinge elements to the tubular strut ends. The shading utilizedin FIG. 4 is intended to indicate the position of a hinge element whichis fastened to the remote end of a strut element while the unshadedelement is intended to represent the hinge element at the near end ofthe strut member.

Any given strut end can, as shown in FIG. 3, have a plurality ofradially disposed multi-hinge elements attached to it. The number ofmulti-hinge elements that can be usefully attached to a given strut endis a function of the inherent symmetry of the axis along which the strutis directed and the position of the neighbouring struts to which it isto be joined. For example, it is known from the teaching of the PearcePat. No. 3,600,825 that any direction that a strut may take emanatingfrom a nodal point of origin will have a characteristic symmetry axis ofn-fold rotational symmetry (or at least a single mirror plane--so-calledbilateral symmetry, e.g. Isoceles triangle).

Usually, although not always, the n-fold rotational symmetry of a givenstrut axis will correspond to the number of adjacent neighbouring strutsto which it must (or may) be attached. Such n-fold rotational symmetrywill usually dictate the angular positioning of the multi-hinge elementsabout the axis of the tubular strut. For example, the embodimentsillustrated in FIG. 3 are based on a four-fold symmetry while theembodiments illustrated in FIG. 4 represent variations based on athree-fold symmetry. In FIGS. 4a, b and c there are illustrated, strutshaving two hinge elements at each end. As could be expected, thepossible variations include the combination where the hinge elements atopposite ends are tangent to the same plane (as in FIG. 4a) or, (as inFIGS. 4b and 4c) only one of the three defined planes has two hingeelements tangent to it.

In FIG. 4d, each end of the strut has three multi-hinge elements equallydisplaced about the circumference. The elements at the opposite end areplaced to intercept the same planes. However, in FIG. 4e, the hingeelements at one end are rotated relative to the hinge elements at theopposite end, so that diammetrically opposite hinge elements are tangentto the same plane.

A modified multi-hinge element 36 is required for use with a squaretubular strut 38. The modification is primarily made to the attachingportion which must be planar in order to attach to the flat side of thestrut 38. As shown in FIG. 5a, a pair of multi-hinge elements arepositioned on opposite sides of the strut 38 while, in FIG. 5b, a pairof multi-hinge elements are positioned adjacent one another, separatedby 90°.

In other variations, a three hinge element embodiment is shown in FIG.5c with hinge elements 36 on three of the four faces while, in FIG. 5dthere is shown a strut 38 with hinge elements 36 on each of the sides.

As in other embodiments, the hinge elements are arranged to be onopposite sides of a plane which passes through the centre of the strut.Struts that are connected in parallel would then have their centreslying in a common plane.

FIG. 5e illustrates an interesting variation of the struts of FIGS.5a-d. Here a square tubular strut 38 utilizes right angled hingingelements 39. These hinging elements 39 are arranged so as to be onopposite sides of a plane which passes through the central axis of thestrut 38 and each hinging element 39 has a right angle between theattaching portion and the hinging portion.

Triangular tubular struts are shown in FIGS. 6a, 6b and 6c. Themulti-hinge element 40 which is connected to the triangular strut 42, ismodified as in FIG. 5 so that the attaching portion 44 is substantiallyplanar and the hinging portion 46 extends to be parallel to a planeincluding the central axis of the tubular strut 42. That plane is aperpendicular bisector of the angle at the apex which is adjacent thehinging portion 46. In FIG. 6a, there is shown a strut with twomulti-hinge elements while in FIG. 6b, three multi-hinge elements areprovided. These struts are useful in applications requiring three-foldand six-fold symmetry.

FIG. 6c illustrates the use of a right angle hinge element 39 as appliedto a triangular strut 42. As before, the shading indicates a hingeelement fastened to a remote end of the strut while the unshaded hingeelements are mounted at the near end of the strut. In the illustratedconfiguration, the hinging surface is tangent to a plane through thecentral axis of the strut that bisects the side upon which the hingeelement 39 is fastened.

In FIG. 7a, there is shown a hinge element 54 which is adapted for usewith a hexagonal tubular strut 56. As with the hinge 40 in FIG. 6, thereis a flat attaching portion 58 adapted to fasten to a surface. Thehinging portion 60 is angled to be tangent to a plane passing throughthe apex and the central axis of the hexagonal tubing 56.

In FIG. 7b, utilizing the convention of shading the hinging elements 54at the remote end of the strut 56, a configuration is shown wherehinging elements at one end are on alternate apices. The hinge elements54 at the other end of the strut 56 similarly alternate, but with arotation of 60°. In the embodiment illustrated in FIG. 7c, six hingingelements 54 are shown disposed around one end of the strut 56. Thisembodiment is used in structures of six-fold symmetry.

Turning next to FIG. 8, there is shown a strut 42, such as is shown inFIG. 6a, connected to a strut 38, such as shown in FIG. 5a. A fasteningelement 32 functions as both a hinge pin and a bolt.

In FIG. 9, which includes FIGS. 9a-9c, there are shown typical strutsbolted together in which different arrangements of multi-hingeattachments angles are assembled into particular configurations. In FIG.9a, for example, a first strut 62, such as is shown in FIG. 4a, 4b or4c, is connected to a second strut 64, such as is shown in FIG. 3a.This, in turn, is connected to another, first strut 62. The resultingstructure provides parallel struts which could support a plane surface.In the alternative configuration of FIG. 9b, three substantiallyidentical first struts 62 are interconnected together.

In the embodiment of FIG. 9c, three struts 66 of the type shown in FIG.4d or 4e, are each connected to a strut 68 such as is shown in FIG. 3d.

While the end view of FIG. 9 creates the impression that each of thestruts is connected in a way that to arrange all of the strut axes to beparallel, it is clear that in typical, triangulated structures, thedifferent struts would be rotated on their hinge axes, so that thetriangulation could be achieved.

For example, in FIG. 10, there can be seen a typical space frame jointin which eight strut ends meet at a single nodal domain, including fourcoplanar struts and four oblique struts. Each strut end has two hingeelements attached to it. The coplanar struts are all identical with a90° angular displacement of hinge elements (such as shown in FIG. 3b),while the oblique members, which are also identical, exhibit a 120°angular displacement of hinge elements, (such as is shown in FIGS. 4d or4e).

When paired hinge elements are bolted together, said bolts may beextended and lengthened to provide a basis for the attachment ofinterstitial panel 70. This is shown schematically in FIG. 11. Such asystem of panel attachment is highly consistent with the structuralbehaviour of fully triangulated framework structures. Since this systeminsures that loads on the panel surfaces, e.g. wind, will be transmitteddirectly to the nodes of the structure, the pure axial (tension,compression) loads will be preserved. This strategy enables optimumefficiency (strength to weight) of the framework.

As was noted above, the multi-hinge joint elements can be produced invarious styles, and in various materials. In FIG. 12, there is shown onealternative style of multi-hinge element which is commonly known as thedouble shear joint. Such a hinge element can be made by forging, castingor stamping or can be produced from sintered metal.

In FIG. 12 a hinge element 74 is shown as a "yoke" or "female" doubleshear element which fastens to a corresponding hinge element 76, that isadapted to fit in the yoke. The combination is secured by a pin or bolt.In the illustration of FIG. 12, the hinge elements are fastened directlyto struts while in FIGS. 13 and 14, the hinge elements illustratedtherein are separate structures which include all of the necessary hingeelements in an end piece that is fastened to the tubular strut. Thissuperficially resembles the approach taught by Fuller, supra, in FIGS.10 and 11.

In FIG. 13, a female yoke 78 is shown which can be inserted and securedto the open end of a tubular strut member. FIGS. 13b and c are sideviews showing the element before and after insertion into the strut.Similarly, FIG. 14 shows three of the female or yoke hinge elements 78coupled to an end piece 80 which includes three male hinge elements. InFIG. 14b, a coupling of two female elements to a single male element isshown.

FIG. 15 shows an alternative hinge element of the triple shear type 82in which two yoke elements are intercoupled in an "overlapping" fashionand secured with a pin. Two struts so equipped are connected in FIG. 15.In this embodiment, the hinge elements 82 are arranged so that thehinging portions are directed inwardly.

In FIG. 16 through 18, there are illustrated yet another style ofmulti-hinge element 84 consisting of a stamped, metal hinge half with arolled end 86. The hinge element 84 is then resistance welded to astrut. FIG. 16a is an exploded view of the connected pair of strutelements illustrated in FIG. 16b.

The placement of hinge elements on struts as shown above, can beemployed no matter what the type of hinge element is used. As seen inFIG. 16, the stamped hinge 84 requires a bend before creating the rolledend 86 so that the axis of the aperture at the rolled end will beperpendicular to a plane passing through the fastening edge of therolled end 86 and the central axis of the strut.

The rolled end 86 is oriented to be exterior of the strut. This differsfrom the orientation of the embodiments of FIG. 15, which are intendedto be used with larger struts in order to minimize the area required forthe attachments. Typically, a more or less normal sized strut would havean outside diameter of under 21/2". Larger diameter struts would then beconsidered oversized and special considerations would dictate theplacement of the hinge elements.

That relationship can best be seen from the end views of FIGS. 17a and17c in which a four-fold symmetry is shown with the rolled endsequiangularly spaced about the strut while in FIG. 17c a three-foldsymmetry is shown with three hinge elements 84 equiangularly displacedabout the strut. FIGS. 17b and 17d represent side views respectivelyillustrating FIG. 17a and 17c.

In FIG. 18, three struts using stamped, metal hinge elements 84 areshown interconnected together. In FIG. 19, four of the struts of FIG.17c are shown connected to the four rolled ends 86 of a strut such as isshown in FIG. 17a.

In FIGS. 20 and 21, the struts of FIGS. 16 through 19 are shownconnected to panel 88. In FIG. 20 the strut of FIG. 17a is utilizedwhile in FIG. 21, the strut of FIG. 17c is utilized. Slight variationsin the panels 88 and modes of attachment may be necessary to accommodatethe angular orientation of the multi-hinge element in order to achieve aplanar structure.

For example, in FIG. 21a, a panel 88 can be directly bolted to a rolledend 86 while a second, parallel panel 88 would first be fastened to anangle iron 90 which would then bolt to a second rolled end 86 of asecond hinge element on the strut. Similarly, in FIG. 21b, amodification of the attachment system of FIG. 20b is required when thethree hinge strut of FIG. 21 is used in place of the four hinge strut ofFIG. 20.

All variations shown in the Figures included herewith constitute viablealternatives to the same system of joining. Which alternatives onechooses would depend on materials, the scale of the struts and joiningcomponents, and the magnitude of the stresses that are likely to beencountered in a given structure as well as other criteria that may beimposed by the designer.

All variations anticipate the basic condition of triangulated spaceframe systems which is that no bending moments are induced in a joint.Forces always remains in an axial mode of either pure compression ofpure tension, up to the point of buckling. Because the multi-hinge jointsystem is intended for use in triangulated structural systems, a rangeof angular accommodation can be anticipated from 30° to 90°, althoughangles of less than 30° can easily be accommodated by multi-hinge jointassemblies.

A typical complex application of the multi-hinge joint system would bethe accommodation of the twenty-six directions of the universal node(disclosed and claimed in the Pearce Pat. No. 3,600,825). In thatelement, twenty-six different struts met at a common nodal domain orpoint. To complete a full universal node would require forty-eight pairsof hinge elements joined together with forty-eight hinge pins or bolts.

As noted above, as few as three struts can be joined in a nodal domainor, as many as one hundred struts can be joined. Therefore, the meetingof twenty-six struts is a condition of only moderate complexity which,when satisfied would produce a fully stable joint.

With the system of the present invention, all structural framingcomponents, including strut lengths and multi-hinge positions can befully prefabricated in the factory, ready for assembly. On site assemblyis simply accomplished by sequential bolting or pinning together ofstrut ends.

It can also be seen that the system is easily adaptable to circulartubes or other geometrical shapes. It has been determined that tubularmembers are desirable because of their high strength to weight ratios.However, it would be within the skill of the art to adapt the presentinvention to strut elements of yet other structural shapes orconfigurations, for example, such as are shown in the patent to Fuller,supra. The individual hinge element can easily be mass produced for eachtype of strut.

Of course, other variations are possible, for example, when dealing withoversize struts that would require a reduced diameter in the area of thehinge element. Yet other variations will appear to those skilled in theart and accordingly, the invention should only be limited by the scopeof the claims appended hereto.

INDUSTRIAL APPLICABILITY

The present invention finds industrial application in the provision ofcivil engineering and other structures.

I claim:
 1. A triangulated structural assembly including a plurality of elongated structural elements, each of which elements is permanently provided with at least two integral connector means at each end thereof and in which each elongated structural element is pivotally connected directly to at least one further structural element in non-colinear alignment by their connector means about a pivot axis which is transverse to the longitudinal axes of the elongated structural elements, said pivot axis being displaced from the central axis of said structural element; each connector means comprising an axially elongated attaching portion about said structural element and an assymetrical radially extending hinging portion along the length thereof and secured to said structural element and including a bore for a pivot pin.
 2. An assembly as claimed in claim 1 in which the pivot axis of each said connector means is disposed within the length of the general envelope of said structural element itself, but outside the general envelope of said structural element.
 3. An assembly as claimed in claim 1 in which said connector means further include an attachment portion contiguous along its length with said hinging portion for securing said connector means to said structural element.
 4. Said hinging portion an assembly as claimed in claim 3 in which the bracket is formed from sheet material and the pivot axis extends normal to the material of said hinging portion.
 5. An assembly as claimed in claim 4 in which said attaching portion is formed to conform with the part of the surface of the structural element to which it is attached.
 6. An assembly as claimed in claim 3 in which said hinging portion of the connector means has an abutment face to engage the corresponding part of a further element to which it may be connected, that abutment face lying transverse to the pivot axis and in a plane which passes through the longitudinal axis of the structural element.
 7. An assembly as claimed in claim 1 in which said hinging portion is attached to the structural element by welding or bonding.
 8. An assembly as claimed in claim 3 in which the bracket is attached to the structural element by means of welding.
 9. An assembly as claimed in claim 3 having a plurality of said connector means disposed around end.
 10. An assembly as claimed in claim 9 in which the plurality of connector means are equally spaced about the longitudinal axis of the structural element.
 11. An assembly as claimed in claim 1 in which the structural elements are formed from circular cross-section tube.
 12. An assembly as claimed in claim 1 in which the structural elements are formed from polygonal cross-section tube.
 13. An assembly as claimed in claim 1 in which the connector means of adjacent ones of the elements are connected by means of a pivot pin.
 14. An assembly as claimed in claim 13 in which each pivot pin comprises a screw-threaded bolt with a retaining nut.
 15. An assembly as claimed in claim 13 in which further structural items are connected to the assembly of said structural elements by means of one or more said pivot pin or pins. 